1. Field of the Invention
The present invention relates to a processing waste liquid treating apparatus attached to a processing device such as a cutting device for cutting a workpiece such as a semiconductor wafer or the like to treat processing waste liquid fed thereto during the processing.
2. Description of the Related Art
In the semiconductor device manufacturing step, the front surface of a generally disklike semiconductor wafer is sectioned into a plurality of areas by predetermined dividing lines called streets arranged in a lattice-like pattern. Devices such as ICs, LSIs or the like are formed on the areas thus sectioned. Thereafter, the semiconductor wafer is cut along the streets to divide the areas formed with the devices to manufacture the individual semiconductor devices. Also optical device wafer in which gallium nitride-based compound semiconductor or the like are laminated on the front surface of a sapphire substrate is cut along streets and divided into individual optical devices such as light-emitting diodes, laser diodes or the like, which are widely used in various electric equipment.
Cutting the semiconductor wafer or the optical device wafer described above along the streets is usually performed by a cutting device called a dicer. This cutting device includes a chuck table adapted to hold a workpiece such as a semiconductor wafer or the like; cutting means provided with a cutting blade for cutting the workpiece held by the chuck table; and processing water supply means for supplying processing water to the cutting blade. In addition, the processing water supply means supplies cutting water to the rotating cutting blade to cool it and supplies the processing water to a portion of the workpiece cut by the cutting blade. Thus, the cutting work is performed.
Cutting scraps produced by cutting silicon or gallium nitride-based compound semiconductor mix in the processing liquid supplied during the cutting as described above. Since the processing waste liquid immixed with the cutting scraps made of the semiconductor material pollutes environment, a waste liquid treating apparatus is used to remove the cutting scraps before reuse or discard. See e.g. Japanese Patent Laid-open No. 2004-230527.
The waste liquid treating apparatus includes a waste liquid storage tank for holding processing waste liquid; a pump for supplying the processing waste liquid held in the waste liquid storage tank; waste liquid filtering means for filtering the processing waste liquid supplied by the pump to purify it into clear water; and a clear water storage tank for holding the clear water purified by the waste liquid filtering means. The waste liquid treating apparatus further includes a clear water supply pump for supplying the clear water held in the clear water storage tank; control means for controlling the constituent means mentioned above; and a console panel equipped with display means for displaying the operating conditions of the constituent means controlled by the control means. A significantly large installation area is required to arrange the constituent means so that a clean room with high maintenance costs cannot be used effectively.